1. Field of the Invention
The present invention relates generally to a ball valve. Particularly, the present invention is directed to a bonded piston seal ball valve.
2. Description of Related Art
Ball valves of all types for varied uses are well known in the art. Applications tend to utilize ball valves where it is desirable to selectively seal or unseal an opening based upon some physical factors such as, for example, rotation or pressure differences. Accordingly, ball valves are often necessary components to any automotive transmission. In those instances, ball valves are utilized to permit a piston to stroke in response to pressure, thus allowing the piston""s clutch pack to be engaged in connection with a gear change.
In operation, pistons in the transmission system engage a particular gear as pressure is applied, and disengage when pressure is relieved. As the pistons of a transmission system rotate, the transmission fluid in the pistons rotates with them and builds up pressure due to centrifugal force. To keep the pressure from building and hence causing different gears to be engaged simultaneously, the pistons are fitted with ball valves designed to allow fluid (and hence pressure) to leak out under certain conditions.
Bonded piston seals are common in transmissions. Bonded piston seals have metal inserts about their perimeter in the piston chamber to create seals. Rubber is often molded over the inner and/or outer ends to maintain a better seal between the insert and the piston shaft and bore, respectively. The ball valve is placed into an opening in the insert. FIG. 3 depicts an embodiment of the prior ball valve designs, with a prior ball valve designated generally as numeral 100. A metal insert 110 of a bonded piston seal is shown. The insert 110 of a bonded piston seal is of a generally circular shape and sits between the piston shaft and the bore. The insert 110 has a rubber seal 130 molded around its inner and outer edges to provide a better seal. The insert 110 also includes an opening 120. A ball valve 100 is then press fit into the opening 120. In other prior art embodiments, the ball valve 100 may be slip fit into the insert 110 and staked for retention, or the ball valve 100 may be press fit into an opening of the piston seal without use of an insert 110.
There are several disadvantages to each of the prior designs. The ball valve 100 exists as a separate component from the insert 110, adding to the cost of manufacture. In addition, care must be taken to ensure that the there is no leakage between the ball valve 100 and the opening 120. Furthermore, performance of the ball valve 100 may be adversely affected if the ball valve 100 is not positioned properly. For example, if the ball valve 100 is cocked slightly to one side, the ball will not seat properly and may seal or leak under improper conditions. Moreover, since each ball valve 100 must be acquired separately, individual performance of piston seals may differ based upon slight variations in dimension, strength, or seat angles in the different ball valves 100.
There thus remains a need for an efficient and economic ball valve that overcomes each of the above disadvantages.
The purpose and advantages of the present invention will be set forth in and apparent from the description that follows, as well as will be learned by practice of the invention. Additional advantages of the invention will be realized and attained by the methods and systems particularly pointed out in the written description and claims hereof, as well as from the appended drawings.
It is an object of the invention to provide an inexpensive ball valve. A feature of an embodiment of the present invention is a dividing member having a seat thereon. In an embodiment of the present invention, the dividing member may be an insert for a bonded piston seal. In other embodiments, the dividing member can be any structure dividing two or more chambers. Another feature of an embodiment of the present invention is a housing over the seat. In one embodiment, the housing may be molded to the insert. A feature of another embodiment of the present invention is a housing and rubber seal unitarily formed. An advantage of the preferred embodiments of the present invention is that ball valves may be more cheaply produced by incorporating the seat as part of the insert. Another advantage is that it is less expensive to insert a ball into a molded housing than to insert an entire valve assembly into a hole in a wall or dividing member of the desired chamber. Yet another advantage is that it is inexpensive to create the housing as part of the rubber seal.
A further object of the present invention is to provide for more consistent valve performance. A feature of an embodiment of the present invention is a valve seat that is formed directly into a chamber wall, dividing member or insert. An advantage of the preferred embodiment is that the chances for misaligning or cocking the valve during use or installation are greatly reduced.
Yet another object of the present invention is to provide for an improved ball valve and chamber. A feature of an embodiment of the present invention is a chamber having a seat formed directly onto a wall of the chamber. Another feature of an embodiment of the present invention is a housing unitarily formed with a wall of the chamber. An advantage of the preferred embodiments is that the device may be more cheaply produced. Another advantage of the preferred embodiment is that valve performance is improved by ensuring stable and proper alignment of the valve seat with the chamber wall.
In brief, a preferred embodiment includes a ball valve comprising: a seat formed in a dividing member having a first opening thereon; a housing over the seat having a second opening defined by a flap defined by an outer diameter and an inner diameter; and a ball in the housing, the ball having a diameter greater than the inner diameter.
Another embodiment includes a ball valve for a bonded piston seal comprising: a bonded piston seal insert, the insert having a seat with a first opening thereon; a housing over the seat, the housing having a flap at an end thereof, wherein the flap is defined by an outer perimeter and an inner perimeter, the inner perimeter defining a second opening; and a ball in the housing, the ball larger than the second opening.
A further embodiment includes a unitarily formed chamber and ball valve comprising: a seat formed in a wall of the chamber, the seat having a first opening; a housing over the seat, the housing having a flap at an end thereof, wherein the flap is defined by an outer perimeter and an inner perimeter, the inner perimeter defining a second opening; and a ball in the cavity, the ball larger than the second opening.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and are intended to provide further explanation of the invention claimed.